| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic sensor having an electric characteristic unchangeable by the state of a load (tank) or a mounting method. SOLUTION: An ultrasonic wave emission face of the ultrasonic sensor is formed not as a plane but as a structure having a hollow, to thereby form a fixed layer of an acoustical coupling material. Therefore, the change of the electric characteristic of the ultrasonic sensor generated at the mounting time on the load (tank) can be removed. |
